This is just a further cosmetic explanation of earlier provided correct answer.

no ip address <ip address1, subnet mask1> secondary

ip address <ip address1, subnet mask1>

      !  it ll overwrite the existing primary ip address.

ip address <ip address2, subnet mask2> secondary

End Reslt

-------------

IP Address 1 became primary and 2 became secondary

If you only have a single mgmt interface, you may be able to swap them by combining both commands on a single line joined with ';' (semicolon).

e.g. current config:

interface mgmt0
ip address 192.168.1.1/24
ip address 10.10.10.1/24 secondary

NOTE: for safety, run from console or connected in via a different VLAN SVI IP if possible... :)

Steps required:
1) Remove current secondary IP (not allowed to have main or secondary IPs conflict/duplicated)
2) Replace current IP with old secondary IP
3) add old IP as secondary IP

Combine all 3 commands into a single command joined with ';' (semicolon), e.g.:

no ip address 10.10.10.1/24 secondary ; ip address 10.10.10.1/24 ; ip address 192.168.1.1/24 secondary

Resulting config:

interface mgmt0
ip address 10.10.10.1/24
ip address 192.168.1.1/24 secondary

I looked into using configuration session/commit, but this does not support interface IP change.

Brian